Answer:
First Samuel 16:14 says, “The Spirit of the LORD had departed from Saul, and an evil spirit from the LORD tormented him.” This is also mentioned in 1 Samuel 16:15–16, 23; 18:10; and 19:9. Why did God let an evil spirit torment Saul? In what way was the evil spirit “from” the Lord?

First, the evil spirit was “from” the Lord in that it was allowed by God to harass Saul. Ultimately, all created things are under God’s control. It is likely that this evil spirit was part of God’s judgment upon Saul for his disobedience. Saul had directly disobeyed God on two occasions (1 Samuel 13:1–14; 15:1–35). Therefore, God removed His Spirit from Saul and allowed an evil spirit to torment him. Likely, Satan and the demons had always wanted to attack Saul; God was now simply giving them permission to do so.

Second, the evil spirit was used to bring David into the life of Saul. This account is recorded immediately following David’s anointing as the future king of Israel. The reader would be wondering how a shepherd boy would become king. First Samuel 16 reveals the first step in this journey. When the king’s servants saw the torment Saul was enduring, they suggested, “See, an evil spirit from God is tormenting you. Let our lord command his servants here to search for someone who can play the lyre. He will play when the evil spirit from God comes on you, and you will feel better” (1 Samuel 16:15–16).

One of the king’s servants referred David to the king, describing the youth as a great harp player, among other things (verse 18). Saul called David to come and found him to be a great comfort: “David came to Saul and entered his service. Saul liked him very much, and David became one of his armor-bearers. Then Saul sent word to Jesse, saying, ‘Allow David to remain in my service, for I am pleased with him.’ Whenever the spirit from God came on Saul, David would take up his lyre and play. Then relief would come to Saul; he would feel better, and the evil spirit would leave him” (1 Samuel 16:21–23).

It is important to note that this evil spirit that troubled Saul was only temporary. The final verse notes that the evil spirit came on multiple occasions to bother Saul, but also it departed from him.

A related question is, does God send evil spirits to torment people today? There are examples of individuals in the New Testament being turned over to Satan or demons for punishment. God allowed Ananias and Sapphira to be filled with the spirit of Satan as a warning and example to the early church (Acts 5:1–11). A man in the Corinthian church was committing incest and adultery, and God commanded the leaders to “hand him over to Satan” to destroy his sinful nature and save his soul (1 Corinthians 5:1–5). God allowed a messenger of Satan to torment the apostle Paul in order to teach him to rely on God’s grace and power and not become conceited because of the tremendous abundance of spiritual truth he was given (2 Corinthians 12:7).

The New Testament reveals how God can use the presence of evil spirits to reveal His power. Jesus showed His power over demons on multiple occasions; every time Jesus cast out a demon, it was an affirmation of the Lord’s authority. The account of Jesus’ casting out the demons who entered a herd of pigs indicates that perhaps as many as 2,000 evil spirits were present, yet they all feared the power of Christ (Mark 5:1–13).

If God does allow evil spirits to torment people today, He does so with the goal of our good and His glory (Romans 8:28). And, just as in Job’s case, Satan and his minions can do only what God allows them to do (Job 1:12; 2:6). They never act independently of God’s sovereign and perfect will and purpose. If believers suspect they are being tormented by demonic forces, the first response is to repent of any known sin. Then we should ask for wisdom to understand what we are to learn from the situation. Then we are to submit to whatever God has allowed in our lives, trusting that it will result in the building up of our faith and the glory of God.

Evil spirits are no match for the power of God. As Ephesians 6:10–12 commands, “Be strong in the Lord and in his mighty power. Put on the full armor of God, so that you can take your stand against the devil’s schemes. For our struggle is not against flesh and blood, but against the rulers, against the authorities, against the powers of this dark world and against the spiritual forces of evil in the heavenly realms.”